Primary immunodeficiency and chronic mucocutaneous candidiasis: pathophysiological, diagnostic, and therapeutic approaches.

Chronic mucocutaneous candidiasis (CMC) is characterized by a chronic or recurrent non-invasive infection, mainly due to Candida albicans, in skin, nails, and mucous membranes, associated in some cases with autoimmune manifestations. The key immune defect is a disruption of the action of cytokine IL-17, whose most common genetic etiology is STAT1 gene gain-of-function (GOF) mutations. The initial appropriate treatment for fungal infections is with azoles. However, the frequent occurrence of drug resistance is the main limitation. Therefore, identification of the underlying inborn error if immunity in CMC may allow to widen therapeutic options aimed at restoring immunological function. Type I and II Janus kinase-inhibitors have been shown to control CMC in cases associated with STAT1 GOF. In this review, we delve into the pathogenesis of CMC and the underlying immune mechanisms. We describe the reported genetic defects in which CMC is the main manifestation. Diagnostic and therapeutic approaches for these patients are also offered.